/* PureAir Lab — lightweight stylesheet (no external deps, PSI-friendly) */
:root{
  --bg:#ffffff; --fg:#1a2027; --muted:#5b6672; --line:#e6eaee;
  --brand:#0e7c66; --brand-dark:#0a5f4e; --accent:#ff8a3d;
  --card:#f7f9fa; --star:#f5a623; --maxw:1080px;
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--fg);
  font:16px/1.65 -apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;}
img{max-width:100%;height:auto;display:block}
a{color:var(--brand);text-decoration:none}
a:hover{text-decoration:underline}
.wrap{max-width:var(--maxw);margin:0 auto;padding:0 20px}

/* Header */
.site-header{border-bottom:1px solid var(--line);position:sticky;top:0;background:var(--bg);z-index:20}
.site-header .wrap{display:flex;align-items:center;justify-content:space-between;min-height:64px;gap:16px}
.logo{font-weight:800;font-size:20px;color:var(--fg);letter-spacing:-.3px;display:inline-flex;align-items:center;gap:8px}
.logo span{color:var(--brand)}
.logo-ico{border-radius:7px}
.nav{display:flex;gap:20px;flex-wrap:wrap}
.nav a{color:var(--fg);font-weight:600;font-size:15px}
.nav a:hover{color:var(--brand)}
.menu-toggle{display:none}

/* Disclosure banner */
.disclosure{background:#fff8ef;border:1px solid #ffe2c2;color:#7a5b32;
  font-size:13px;padding:10px 14px;border-radius:8px;margin:18px 0}

/* Hero / headings */
h1{font-size:34px;line-height:1.2;margin:18px 0 10px;letter-spacing:-.5px}
h2{font-size:25px;margin:34px 0 12px;letter-spacing:-.3px}
h3{font-size:20px;margin:22px 0 8px}
.lead{font-size:18px;color:var(--muted);margin:0 0 8px}
.updated{font-size:13px;color:var(--muted);margin:0 0 16px}
p{margin:0 0 14px}
ul,ol{margin:0 0 16px;padding-left:22px}
li{margin:6px 0}

/* Breadcrumbs */
.crumbs{font-size:13px;color:var(--muted);margin:16px 0 4px}
.crumbs a{color:var(--muted)}

/* Comparison table */
.table-scroll{overflow-x:auto;margin:18px 0}
table.cmp{border-collapse:collapse;width:100%;min-width:560px;font-size:15px}
table.cmp th,table.cmp td{border:1px solid var(--line);padding:10px 12px;text-align:left;vertical-align:top}
table.cmp th{background:var(--card);font-weight:700}
table.cmp tr:nth-child(even) td{background:#fbfcfd}
.pill{display:inline-block;background:var(--brand);color:#fff;border-radius:999px;
  padding:2px 10px;font-size:12px;font-weight:700}

/* Product card */
.pick{border:1px solid var(--line);border-radius:14px;padding:20px;margin:18px 0;background:var(--card)}
.pick .badge{display:inline-block;background:var(--accent);color:#fff;font-weight:700;
  font-size:12px;padding:3px 10px;border-radius:999px;margin-bottom:8px}
.pick h3{margin-top:4px}
.proscons{display:flex;gap:24px;flex-wrap:wrap;margin:12px 0}
.proscons div{flex:1;min-width:220px}
.pros li::marker{color:var(--brand)}
.cons li::marker{color:#d0554a}
.btn{display:inline-block;background:var(--accent);color:#fff !important;font-weight:700;
  padding:12px 22px;border-radius:10px;margin-top:8px;text-decoration:none}
.btn:hover{background:#e9762b;text-decoration:none}
.specs{font-size:14px;color:var(--muted);margin:6px 0 0}

/* FAQ */
.faq{margin:24px 0}
.faq details{border:1px solid var(--line);border-radius:10px;padding:12px 16px;margin:10px 0;background:#fff}
.faq summary{font-weight:700;cursor:pointer}
.faq p{margin:10px 0 2px}

/* Related */
.related{background:var(--card);border-radius:14px;padding:18px 20px;margin:28px 0}
.related h2{margin-top:0;font-size:19px}
.related ul{margin:0;list-style:none;padding:0;display:grid;grid-template-columns:1fr 1fr;gap:8px 20px}

/* Ad slot placeholder */
.ad-slot{margin:24px 0;text-align:center;color:#b9c2ca;font-size:12px;
  border:1px dashed var(--line);border-radius:10px;padding:14px;min-height:90px;
  display:flex;align-items:center;justify-content:center}

/* Hero + diagrams */
.hero-img{width:100%;height:auto;border-radius:16px;border:1px solid var(--line);margin:18px 0}
.diagram{width:100%;height:auto;border:1px solid var(--line);border-radius:12px;
  background:#fff;padding:8px;margin:18px 0}

/* Cards grid (home) */
.grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px;margin:22px 0}
.gcard{border:1px solid var(--line);border-radius:14px;padding:18px;background:#fff;
  border-top:4px solid var(--brand);transition:box-shadow .15s}
.gcard:hover{box-shadow:0 4px 18px rgba(14,124,102,.10)}
.gcard h3{margin:0 0 6px;font-size:18px}
.gcard p{font-size:14px;color:var(--muted);margin:0}

/* Footer */
.site-footer{border-top:1px solid var(--line);margin-top:48px;padding:28px 0;color:var(--muted);font-size:14px}
.site-footer .wrap{display:flex;justify-content:space-between;gap:16px;flex-wrap:wrap}
.site-footer a{color:var(--muted)}

@media(max-width:720px){
  h1{font-size:27px}h2{font-size:21px}
  .grid,.related ul{grid-template-columns:1fr}
  .nav{display:none;position:absolute;top:64px;left:0;right:0;background:#fff;
    flex-direction:column;padding:14px 20px;border-bottom:1px solid var(--line)}
  .nav.open{display:flex}
  .menu-toggle{display:block;background:none;border:1px solid var(--line);
    border-radius:8px;padding:8px 12px;font-size:16px;cursor:pointer}
}